HTTP/3 is the designated name for the coming next version of the protocol that is currently under development within the QUIC working group in the IETF.
HTTP/3 is designed to improve in areas where HTTP/2 still has some shortcomings, primarily by changing the transport layer. HTTP/3 is the first major protocol to step away from TCP and instead it uses QUIC.
Daniel Stenberg explains HTTP/3 and QUIC. Why the new protocols are deemed necessary, how they work, how they change how things are sent over the network, what some of the coming deployment challenges will be and to top it off: how to start playing with it using curl, browsers, Wireshark and more.